How to bake multiple audio sounds to f curve?
Bake to custom properties to drive from.



As an example I've made 3 custom properties on the default cube.
Add a keyframe and bake to sound for each.



Image. Baked prop, added keyframe to prop2.

Now let's say we want to drive the cube's x location by these props.

Add a driver to the location.x field. Hover over with mouse, right click, add drivers &gt; manually create later single.  Put the graph editor in Drivers mode, select the location.x driver, hit N and choose drivers tab.



with scripted expression chosen (default) and the "use self" option checked, can type (or paste) in an expression, where self is the Cube object, adnd self["prop"] is the value of baked property "prop".

The following sums the three.

self["prop"] + self["prop1"] + self["prop2]"


or another way using sum

sum([self["prop"], self["prop1"], self["prop2]"])    


average

sum([self["prop"], self["prop1"], self["prop2]"]) / 3


the maximum.

max([self["prop"], self["prop1"], self["prop2]"])


Or if you cannot add the properties to what you are animating, can set up the drivers the old fashioned way  with variables.  Add a single property type variable for each, select the Cube as the target object and the datapath is ["prop"] for "prop"



The expression uses the variable names, I've used p0 , p1, p2.  Similarly to above, the sum would be.

sum([p0, p1, p2])


or by choosing 'SUM' as the driver type.